Re: GPMC in device tree

On Tue, 2015-08-04 at 23:26 +0300, Ran Shalit wrote:

On Tue, Aug 4, 2015 at 9:54 PM, Scott Wood [off-list ref] wrote:

quoted

On Tue, 2015-08-04 at 18:29 +0300, Ran Shalit wrote:

quoted

Hello,

I would please like to ask if describing flash nor used with GPMC,
whould be done as described in:
https://www.kernel.org/doc/Documentation/devicetree/bindings/mtd/gpmc-nor.txt
It is described in the above link as "TI's GPMC", so I'm not sure if
it is relevent for powerpc too.

That binding is for TI GPMC.

Are you saying you have some PPC chip that has a flash controller called 
GPMC?

-Scott

Hi Scott,

Thanks, I've worked with TI's chips, so I now understand that I made
here some confusion...
It is GPCM , not GPMC, my mistake.
We already configured it in u-boot, but on doing read/write from
kernel it doesn not work.
It seems that for the linux to use the correct driver, we need to
define the nor in the device tree.
Is there any example how to define nor GPCM in device tree ? Is it
possible not to override the existing GPCM configuration ?

Pretty much all of the mpc8xxx/qoriq device trees have GPCM NOR defined.  See 
Documentation/devicetree/bindings/powerpc/fsl/lbc.txt and examples such as 
arch/powerpc/boot/dts/p4080ds.dts (part of the lbc node is in 
arch/powerpc/boot/dts/fsl/p4080si-post.dtsi).

Linux will not change the GPCM configuration.

-Scott